Startup procedure for all anion methods Startup procedure for all cation methods
Sample preparation for anions in water |
We have two separate Dionex DX-500 ion chromatograph systems, both with conductivity detectors, autosamplers, and eluant generators. One is dedicated to cations and the other is dedicated to anions and silica. The instrument for anions and silica also has a spectrophotometer detector. These instruments are capable of analyzing many inorganic ions and some organic acids at concentrations that range into the middle to low ppb range. Samples must be in water solutions, not too concentrated, too acidic, or too alkaline.
Routinely analyzed ions
| Anion System | Cation System | ||
| Species | Detection limit, ppb | Species | Detection limit, ppb |
| F- | 1 | Li+ | 1 |
| Cl- | 10 | Na+ | 10 |
| Br- | 10* | K+ | 10 |
| NO2- | 10 | NH4+ | 10 |
| NO3- | 10 | Mg2+ | 20 |
| SO42- | 15 | Ca2+ | 20 |
| PO43- | 25 | Sr2+ | 50 |
| Glycolate | 20 | Requires additional standards | |
| Acetate | 15 | Ba2+ | 100 |
| Formate | 10 | ||
| Propionate | 25 | ||
| Methyl sulfonate | 25 | ||
| Oxylate | 50* | ||
| Requires post-column reagent setup | |||
| SiO2(aq) | 200 | ||
| *Low detection limits only possible in low sulfate samples. | |||
The instrumentation described here was funded in part by the National Science Foundation, grant DUE-9751725, and grants from the Sherman-Fairchild Foundation and the Kresge Foundation.
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Schenectady, NY 12308 U.S.A. |